Fix undefined behavior regarding pData

pData is a void pointer, and even though the address at request.pData[2] is being cast to that of a const UInt8 pointer, the request.pData has to be converted first BEFORE doing any pointer arithmetic. For this reason, it is best to write this it as a pointer sum, rather than an array.

diff --git a/backend/usb-darwin.c b/backend/usb-darwin.c
index 7c25905319e0943f585b85a811f98a6aca1da06c..b17a9b382ab6a4fb6fbf4c75248d992ee0838aea 100644 (file)
--- a/backend/usb-darwin.c
+++ b/backend/usb-darwin.c
@@ -1616,14 +1616,14 @@ static CFStringRef copy_printer_interface_deviceid(printer_interface_t printer,
 
                        if (actualLength > 2 && actualLength <= bufferLength - 2)
                        {
-                               ret = CFStringCreateWithBytes(NULL, (const UInt8 *) &request.pData[2], actualLength - 2, kCFStringEncodingUTF8, false);
+                               ret = CFStringCreateWithBytes(NULL, (const UInt8 *)request.pData + 2, actualLength - 2, kCFStringEncodingUTF8, false);
                        }
                        else if (actualLength > 2) {
                                err = sendRequest(actualLength);
                                if (err == kIOReturnSuccess && request.wLenDone > 0)
                                {
                                        actualLength = OSSwapBigToHostInt16(*((UInt16 *)request.pData));
-                                       ret = CFStringCreateWithBytes(NULL, (const UInt8 *) &request.pData[2], actualLength - 2, kCFStringEncodingUTF8, false);
+                                       ret = CFStringCreateWithBytes(NULL, (const UInt8 *)request.pData + 2, actualLength - 2, kCFStringEncodingUTF8, false);
                                }
                        }
                }
@@ -1817,7 +1817,7 @@ static CFStringRef copy_printer_interface_indexed_description(printer_interface_
        if ((description[0] & 1) != 0)
                description[0] &= 0xfe;
 
-       char buffer[258] = {};
+       char buffer[258] = {0};
        unsigned int maxLength = sizeof buffer;
        if (description[0] > 1)
        {